1. Field of the Invention
The present invention relates to a display apparatus of full color display having organic EL (electroluminescent) elements of three colors of red light emission, green light emission, and blue light emission.
2. Description of the Related Art
As a technique of increasing the luminous efficiency of the display apparatus employing the organic EL elements of three colors of red light emission (R), green light emission (G), and blue light emission (B), Japanese Patent Laid-Open No. 2000-323277 discloses a technique of varying the film thickness of functional layers other than light emitting layers of organic EL elements for each emission color. This is a technique of increasing the luminous efficiency by an optical interference structure of strengthening the peak wavelength of the emission spectrum for each emission color.
Further, Japanese Patent Laid-Open No. 2008-288201 discloses organic EL element which has achieved high efficiency and long life by providing an auxiliary layer containing materials different from those of a hole injecting layer and having hole mobility higher than that of the materials of the hole injecting layer between a light emitting layer and the hole injecting layer of each of organic EL elements of red light emission and green light emission.
However, the display apparatus disclosed in Japanese Patent Laid-Open No. 2008-288201 has a possibility such that the drive voltage becomes high depending on the constituent materials of the hole injecting layer, the light emitting layer, and the auxiliary layer.